Method for processing cheese curds

ABSTRACT

An enclosed food processing device is provided having one or more conveyor belts and vertical agitators positioned above the belt. The agitators have forward and backward prongs that stir the food being processed without causing physical damage to it. The food enters the device through an inlet and is evenly distributed across a draining screen by an inlet deflector plate, which is adjustable to account for the different rates at which the food may flow into the device. Ramps are positioned under the device to collect liquid drained from the food, and the ramps have independent segments that separate the liquid based on the stage of the process at which it is drained from the food. A salting apparatus is provided for conveying salt to the food to be processed. The salt is dispensed in proportion to the amount of food to be salted. Salt is moved from a salt hopper into a chamber by a rotating dispensing wheel. The salting apparatus has a pump that moves a fluid, such as filtered air, through a Venturi pickup tee, where it creates a partial vacuum that pulls salt into the airstream from the chamber. The salt then is pushed through stationary salt distribution tubes and applied to the food to be salted.

This is a continuation of application Ser. No. 08/567,087, filed Dec. 4,1995, now U.S. Pat. No. 5,704,280.

TECHNICAL FIELD

The present invention relates generally to the field of food processingequipment. More particularly, the present invention relates to a devicefor processing food products, such as cheeses. The device comprises ahorizontal conveyor belt over which is mounted a plurality of generallyvertical agitators, thus permitting uniform mixing of the food withminimum physical damage to the food. Salt is dispensed in proportion tothe amount of food being processed, evenly distributed by staggeredstationary salt nozzles over the food being processed, and mixed intothe food by the agitators.

BACKGROUND OF THE INVENTION

The present invention is suitable for producing a variety of cheeses(designated herein as "stirred curd" cheeses), including American stylecheeses, such as current manufacture, cheddar, Colby, American, andother washed curd varieties; Italian style cheeses, such as mozzarella,pizza cheese, Parmesan, Romano, and provolone cheeses; semi-softcheeses, such as brick, Edam, Gouda, Muenster, Monterey Jack, and pepperjack; and Swiss varieties, such as traditional Swiss, baby Swiss, andJarlsberg cheeses. It is suitable for salting any type of food product,including these and other types of cheeses. Cheesemakers have strongfinancial incentives to ensure that these cheeses are made up of uniformsized curds and have moisture levels that fall within specific rangesprescribed by government and industry bodies. In the United States, theUnited States Department of Agriculture (U.S.D.A.) prescribes the rangesfor each type of cheese. The cheese moisture level is greatly affectedby salt content and distribution.

For about the last twenty-five years, stirred curd cheeses have beenproduced in large, open, tub-like curd tables. Curd tables have verticalagitators mounted on an assembly above the table. As the assembly movesback and forth above the table, the cheese curds are mixed. The verticalagitators ensure that the curds, when mixed, are of uniform size.Thomson, U.S. Pat. No. 3,490,751, issued Jan. 20, 1970; Naulin, U.S.Pat. No. 1,499,026, issued Jun. 24, 1924; and McKinnon, U.S. Pat. No.794,421, issued Jul. 11, 1905, disclose assemblies that stir cheesecurds.

Curd tables have serious disadvantages, however. First, making stirredcurd cheeses on a curd table is a labor-intensive process. Thecheesemaker must start with an empty table, and then fill it with curdsand whey. As the curds are mixed and processed, salt must be added tothe curds by hand at the proper point in the processing. After mixingand processing the curds, the agitator attachments are removed andreplaced with attachments that scoop the product from the table. Becausethe assembly can remove the product from the curd table only in smallscoops, and cannot remove it all at once, the process of removing thecurds is time consuming and labor-intensive. To make matters worse,because the assembly is not able to remove curds from the corners andedges of the curd table, after the assembly has been used to remove mostof the curds the cheesemaker manually must remove the product thatremains in the corners and edges of the curd table. Further, becausesome curds must sit for longer periods of time than others during theremoval process, it is difficult to ensure that moisture levels areuniform in all of the curds. Specifically, because moisture is lost asthe curds sit, the curds that are removed earlier will have a highermoisture content than those that are removed later.

In addition, the sequential nature of cheese curd processing on a curdtable makes it difficult to obtain uniform salt concentrations andconsistent levels of acid development. Bacteria are added to obtain theproper acid levels in the cheese; the acid develops at a rate that is afunction of the amount of bacteria added and the time the bacteria areallowed to work. When the acid level is within the desired range, usersof the curd table must spread salt over the curds manually. Because thesalt is distributed by hand, uniform salt dispersion is inherentlydifficult; and because it takes several minutes to distribute salt overthe curds, curds that are salted first are salted at an earlier stage ofacid development than are those that are salted later. In addition,because it takes the cheesemaker several minutes to apply salt to thecurds, the salt is not applied at a single point in the process. Theresult of these difficulties is that the acid development and moisturecontent of the curds are not uniform. Finally, this salting process alsois labor-intensive, and inconsistent salt concentrations result becausethe quantity of cheese delivered from the vat to the curd table may varyfrom batch to batch.

Curd tables have other disadvantages, as well. Because the tables areopen, the curds are exposed to airborne contaminants, the rate at whichprocess heat is lost cannot be controlled, and moisture is lost into theatmosphere. Furthermore, the agitator assemblies are complex and requiresignificant maintenance. In addition, curd tables drain the whey fromthe curds by means of a mesh screen at the bottom of the table. As thecurds are mixed, however, they are pushed across the screen repeatedly,which effects a grating action on the curds. This grating action causessmall particles, called curd fines, to be lost from the curds and passthrough the screen, thus reducing yields.

When compared to curd tables, conveyor belt systems save labor. The beltsystems that currently are in use were developed approximately fifteenyears ago. They use horizontal agitators, which have sharp prongs thatphysically alter the curds by knitting them together and then grindingthem up. Latimer et al., U.S. Pat. No. 4,538,510, issued Sep. 3, 1985,and Brockwell, U.S. Pat. No. 4,309,941, issued Jan. 12, 1982, discloseconveyor belt systems with horizontal agitators. Although systems withhorizontal agitators are suitable for some types of cheeses, they arenot suitable for processing stirred curd cheeses because they physicallydamage the cheese curds and cannot produce uniform sized cheese curds.

Horizontal agitator systems also have several inherent processingdisadvantages. When the curds and whey are dispensed onto the conveyorbelt, the mixture is of varying depths or thicknesses. Horizontalagitators are not able to level the mixture across the width of thebelt, so mixing is not uniform. Furthermore, because the horizontalagitators tend to grind the cheese, they produce curd fines, thusreducing yields and causing profits to be lost. Also, because horizontalconveyor systems produce curds of different sizes, moisture content andsalt penetration varies from curd to curd.

There also are disadvantages to the oscillating boom salting apparatusescurrently used with conveyor belt systems. First, oscillating boomsconsist of many moving parts, and thus are expensive to manufacture andto maintain. More important for cheese processing purposes is that thebooms apply more salt to the food at each end of the oscillation cycle,and thus do not apply salt to the curds in a uniform manner.

These salting problems are exacerbated by the use of the horizontalagitators with conveyor belts. Because the horizontal agitators cannotlevel the height of the curds across the width of the belt, the saltconcentration varies based on the height of the curd mass where the saltis applied. Furthermore, horizontal agitators are unable to mix the saltuniformly across the width of the belt, and instead tend only to pushthe salt in the same straight-line direction in which the food alreadyis travelling on the conveyor belt. In addition, horizontal agitatorsspin in a single location, so they are not effective for stirring thefood.

Horizontal agitator systems also have sanitation problems. The bearingsused with horizontal agitators are subject to large loads, and thebearings wear out and begin to leak. Conversely, cleaning materials mayleak into and damage the bearings. Significant maintenance is requiredto detect and correct leakage problems as soon as they occur.

Neither the curd tables nor the conveyor belt systems provides amechanism for monitoring the moisture level of the cheese curds. Themoisture levels therefore cannot be measured until the next day. Becausethe moisture levels in fully processed cheese cannot be adjusted, if themoisture levels fall outside prescribed parameters, the entire previousday's production of cheese must be disposed of at less than fair marketvalue for that type of cheese.

There is an unmet need for a food processing device that allowsprocessing of large quantities of stirred curd cheeses while maintainingthe physical consistency and integrity of the curds, and at the sametime solves the timing problems associated with curd tables and reducesthe amount of labor required to process the cheese curds. It furtherwould be desirable if the food processing device had a mechanizedsalting apparatus that did not have moving parts, but that did spreadthe salt evenly over the food being processed and in proportion to theamount of food being processed.

SUMMARY OF THE INVENTION

The present invention is directed to a food processing device. Theinvention comprises an elongated housing. In the preferred embodiment,the housing is enclosed. A curd and whey inlet is positioned at thefirst end (the upstream end) of the housing, and an inlet deflectorplate is positioned next to the curd and whey inlet. The distancebetween the curd and whey inlet and the inlet deflector plate may beadjusted so as to be proportioned to the rate at which the curds andwhey flow through the curd and whey inlet.

A mixture of curds and whey from the manufacturing vats enters theinvention through the curd and whey inlet, and is deflected by the inletdeflector plate and deposited onto a draining screen. In the preferredembodiment, the draining screen is a wedge wire draining screen. Asuitable wedge wire draining screen may be purchased from JohnsonFiltration Systems of St. Paul. In the preferred embodiment, the angleof the draining screen is adjustable with respect to the curd and wheyinlet. As the mixture slides down the draining screen and onto theconveyor belt, a substantial portion of whey is drained from the curdsand is collected.

A presalt tube apparatus is positioned near the entrance of the deviceto apply an initial salting to the curds. This initial salting, alsocalled a "presalt," is applied while the temperature of the curds ishigh to encourage the formation of films, which help keep the curds fromknitting together. Additional salt tube apparatuses are mounted towardthe second end (the downstream end) of the housing to salt the curdsmore extensively.

The conveyor belt allows whey to drain from the curds without producingcheese fines. In the preferred embodiment, the belt is made ofinterconnected segments between which liquid may flow. Such a belt maybe purchased from Intralox, Inc. of Harahan, Louisiana, or any othersuitable supplier. Inclined surfaces are positioned under the conveyorbelt to drain whey toward collecting receptacles. The inclined surfacesare positioned independently so that whey drained from nonsalted andpresalted curds is collected separately from whey drained from the curdsafter they have received their more extensive salting later in theprocessing.

Agitators are positioned above the conveyor belt, along the length ofthe belt, to agitate the curds. In the preferred embodiment, eachagitator has an axis of rotation that is generally perpendicular to theupper surface of the material being processed. Because the curds cool asthey move down the belt, they are less likely to knit together towardthe downstream end of the device. They thus need more agitation towardthe upstream end of the device, and less agitation toward the downstreamend of the device. Accordingly, in the preferred embodiment, theagitators are spaced farther apart toward the device's downstream endthan toward its upstream end, thus permitting the use of fewer agitatorsand agitator drive means along the length of the device. However, theagitators may be positioned in any manner suitable to the application.For example, it may be desirable to position the agitators so that theyagitate an area that overlaps the area agitated by adjacent upstream ordownstream agitators.

Any number of agitators also may be used across the width of the belt.In the preferred embodiment, the agitators are positioned side by side,in pairs, across the width of the belt, and the area agitated by eachagitator overlaps the area agitated by its adjacent paired agitator. Thepaired agitators are spaced along the full length of the conveyor belt,as has been described.

Each agitator may rotate in either the same or in the opposite directionfrom that of the agitators adjacent to it across the width of the beltand along the length of the belt. In the preferred embodiment, theagitators in each pair across the width of the belt rotate in oppositedirections.

It is contemplated that many types of agitators would work with thepresent invention. For example, a horizontal agitator with bluntattachments that tended to scoop and stir the curds, instead of thesharp finger-like attachments currently used with horizontal agitators,would produce stirred curd cheeses. Similarly, agitators with an axis ofrotation that is angled into the curds, rather than strictlyperpendicular to the belt, would be within the scope of the presentinvention. Such agitators could be mounted either to the sides or top ofthe food processing device. It is contemplated that other agitatorconfigurations also may be suitable to practice the present invention,so long as the agitators stir the curds without physically damagingthem. In the preferred embodiment, however, each agitators has an axisof rotation that is oriented generally vertically with respect to theplane of the upper surface of the material being processed, and mostpreferably the axis of rotation is perpendicular to the upper surface ofthe material being processed. This embodiment is preferred because itallows effective stirring, and thus produces the most uniform mixing ofthe curds. Any agitator with a generally vertical axis of rotation issuitable to practice the invention, regardless of the agitator'sconfiguration and regardless of whether it has a vertical member. In thepreferred embodiment, each vertical agitator comprises a horizontalmember that is held in place above the curds by a fixed axis verticalsupport member attached to drive means.

Each generally vertical agitator may have any suitable attachments thatstir the curds without physically damaging them. In the preferredembodiment, the attachments comprise forward and rearward prongs. Theprongs revolve about the agitator's generally vertical axis of rotation.As used herein, "revolve" means either "rotate" or "revolve." Theforward prongs curve as they approach the belt so that the bottom end ofeach forward prong points in the direction that the prong is travelling,thus enabling the prong to scoop curds from the belt surface withoutphysically damaging them. As depicted in the figures submitted herewith,the forward prongs are made of rods, and thus have circularcross-sections. In the preferred embodiment, the forward prong has arectangular cross-section, with the wide portion of the prong beingparallel to the belt. A suitable dimension for the cross-section of thisforward prong is roughly two inches by one-half inch. The tip of theforward prong is rounded so as not to damage the curds. The rearwardprongs also may have any suitably shaped cross-section, but a circularcross-section is preferred. The rearward prongs extend into the curds,thus stirring them and breaking up clumps as the vertical agitatorrotates.

The forward and rearward prongs may be arranged in any manner andnumber. In the preferred embodiment, the rearward prongs are closer tothe agitator's axis of rotation than are the forward prongs. It may bedesirable in some applications, however, to alternate or otherwisearrange the forward and rearward prongs from the agitator's axis ofrotation outward to the edge of the agitator's reach. The prongs alsomay be provided in any number, as long as there is at least one prong,either forward or rearward, on each agitator. In the preferredembodiment, more than one grouping of prongs will be operably connectedto the agitator's axis of rotation, and each grouping will comprise oneforward prong and more than one rearward prong.

Any suitable drive means may be used for the agitators. In addition, anydesired ratio of drive means to agitators may be used; the ratio mayvary anywhere from having all agitators driven by a single drive meansto having each agitator driven by its own dedicated drive means. In thepreferred embodiment, multiple drive means are used. More specifically,the device uses one drive means for each pair of vertical agitators.Also in the preferred embodiment, a sealed, raised lip is placed on eachgenerally vertical shaft to prevent fluids from leaking from the bearingor drive means into the food stream.

In a preferred embodiment, a temperature sensor detects the temperatureof the curds. This temperature sensor may be located anywhere, butpreferably is located midway along the length of the housing. Also in apreferred embodiment, ventilation ducts are attached to the housing. Inthe most preferred embodiment, the temperature sensor is operablyconnected to the ventilation ducts, thus controlling the amount ofairflow over the curds in accordance with the temperature of the curds,and thereby allowing the curds to be processed at the desiredtemperature.

In addition, to assist in maintaining the proper moisture content of thecurds, a moisture sensing device may be provided. The moisture sensingdevice informs the cheesemaker whether the curds' moisture levels arewithin proper parameters. In the preferred embodiment, the moisturesensing device is positioned toward the downstream end of the device.

Various cleaning nozzles are located along the length of the belt. In apreferred embodiment, some take the form of spray balls, which areparticularly suited to cleaning the inside of the housing, while otherstake the form of spray bars, which are particularly suited for cleaningthe conveyor belts.

Salt is dispensed into the tube apparatuses by a salt dispenser. Thesalt dispenser and tube apparatuses may be used to apply salt to anytype of food being processed, and to any type of cheese being processed,whether of the stirred curd or milled varieties. It is to be noted thatthe salt dispenser and salt tube apparatuses may be used independentlyof the conveyor, the agitators, or both, but that there is a synergisticeffect between the systems.

In the preferred embodiment, a quantity sensor measures the quantity ofcurds on the belt. The quantity sensor may measure the quantity of curdsby any suitable means, including by measuring either the depth or massof curds on the belt. In the most preferred embodiment, the quantitysensor measures the depth of curds on the belt. The quantity sensor maybe positioned anywhere on the housing, but preferably is positionedtoward the downstream end of the housing, under the salt tubeapparatuses. In the preferred embodiment, the quantity sensor isoperably connected to the salt dispenser, and directs the salt dispenserto release an amount of salt appropriate for the quantity of curds beingprocessed on the belt.

The salt dispenser comprises a chamber member and other componentsdescribed herein. It is connected to and receives salt from a salthopper, and it dispenses the salt into the tube apparatuses. A supply ofsalt is provided to the salt hopper. To ensure that the salt flowsfreely from the salt hopper into the chamber member, the salt hopper hassteep sides and a bin vibrator is attached to the sides of the salthopper. A chamber member is positioned under the salt hopper, and an airinlet is attached to the side of the chamber member. In a preferredembodiment, a plurality of salt hoppers are used, and the inlets for thechamber members are connected so that only one filter is required. Inthe most preferred embodiment, four salt hoppers are used. The middleend opening of a Venturi pickup tee is connected to the lower end of thechamber member. A pump attached to a first end opening of the Venturipickup tee pushes air that has passed through a high-efficiency filterinto the Venturi pickup tee.

Each tube apparatus consists of hollow tubes connected to a second endopening of the Venturi pickup tee. The tube apparatus's distributionends are spaced over the food to be salted in a manner that ensures thatthe salt is applied uniformly to the food. In a preferred embodiment,each distribution end terminates in a duckbill-shaped portion, thusenhancing the even spreading of the salt. If the salt is being appliedto food being processed on a conveyor belt, the duckbill ends ensurethat the salt is spread evenly over the width of the belt.

A vertically oriented dispensing wheel is located inside the chambermember. The dispensing wheel has a plurality of openings. In itspreferred embodiment, the dispensing wheel has a plurality of teethseparated by large gaps. When the wheel turns, salt is moved from thetop portion of the chamber member to the bottom. The Venturi pickup teecreates a partial vacuum in the lower portion of the chamber member,thereby pulling the salt from the lower portion of the chamber memberinto the airstream. The salt is carried into the chamber member in airthat enters the system through the makeup inlets on the chambers.

In the preferred embodiment of the invention, air is used to convey thesalt. The pump will take the form of an air blower, and the fluid thatenters the chamber members through the makeup inlets is air.Nevertheless, other fluids including water may be used to convey thesalt in the present invention. It is contemplated that any source ofsuitable fluid will suffice to practice the present invention, and thusthat the invention may be practiced without a pump when a fluid is usedthat is propelled by other forces, such as gravity or a municipal watersupply.

Drive means are attached to the dispensing wheel. The drive meanspreferably is a motor with a direct current proportioner. In a preferredembodiment of the present invention, a quantity sensor measures theamount of food to be salted. The quantity sensor is operably connectedto the drive means and varies the rate at which the wheel turns, therebycontrolling the amount of salt dispensed to ensure that the properproportion of salt is applied to the food being processed.

In the preferred embodiment of the invention, one tube apparatus will beprovided for each salt hopper, with the tube apparatus connected to thesalt hopper through the Venturi pickup tee, chamber member, and othercomponents described herein. However, any ratio of tube apparatuses tc,salt hoppers may be used in the practice of the invention. For example,it may be desirable in certain applications to have a plurality of salthoppers for each tube apparatus, and it may be desirable in otherapplications to have a plurality of tube apparatuses for each salthopper.

A primary object of the present invention is to provide a machine forprocessing a stirred curd cheese that is closed to the atmosphere andthat easily may be cleaned. Another object of the invention is toproduce cheese curds that have been drained properly of whey, have beensalted, have achieved a proper acidity level, are uniformly mixed, andare of consistent size. Further objects of the invention are to providefor consistent salt distribution, proper temperature control, consistentmoisture control, and less generation of cheese fines. It is yet anotherobject of the present invention to reduce costs for labor, maintenance,and space requirements. A further object of the present invention is toprovide a salting apparatus that evenly distributes salt over the foodbeing processed, and that applies an amount of salt that is inproportion to the quantity of food being salted. Still another object ofthe present invention is to provide a salting apparatus that has onlyminimal moving parts.

These and other objects of the present invention will become apparentwith reference to the drawings, the description of the preferredembodiment, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the present invention.

FIG. 2 is a side elevational view with parts cut away to show theinterior of the food processing device.

FIG. 3 is a top view with some internal components shown in phantom.

FIG. 4 is a fragmentary sectional view taken along line 4--4 in FIG. 3.

FIG. 5 is a fragmentary sectional view taken along line 5--5 in FIG. 4.

FIG. 6 is a fragmentary sectional view taken along line 6--6 in FIG. 3.

FIG. 7 is a elevational side view of the salt dispenser and a frontelevational view of a tube apparatus.

FIG. 8 is a elevational side view of the salt dispenser.

FIG. 9 is a sectional front view of the salt dispenser.

FIG. 10 is a front elevational view of a curd sensor and of a tubeapparatus mounted across the width of a conveyor belt.

FIG. 11 is a fragmentary sectional view taken along line 11--11 in FIG.3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 depicts a food processing device 10 constructed in accordancewith the present invention. The device 10 consists of an elongatedhousing 12. In the preferred embodiment, the housing is enclosed inorder to control heat and moisture levels, keep out contaminants, andallow efficient internal mechanized cleaning. A curd and whey inlet 14is attached to the front of the housing 12 to allow curds and whey to bedispensed into the device 10. A temperature sensor 16 is mounted midwayalong the housing 12 and is operably connected to ventilation ductwork18, thereby controlling the amount of cool air that circulates into thedevice 10 to control the temperature of the curds. The temperaturesensor 16 may be a side-mounted probe or, as shown in the preferredembodiment, a top-mounted infrared device.

A presalt tube apparatus 20 is connected on top of the housing 12 towardthe upstream end of the device 10 to allow salt to be applied to thecurds at the beginning of the processing. Salt tube apparatuses 22 areconnected to the top of the housing 12 toward the downstream end of thedevice 10, thus allowing the product to be salted toward the downstreamend of the processing. In the preferred embodiment, each salt tubeapparatus 22 is identical to each other and to presalt tube apparatus20. Accordingly, reference may be made herein simply to a tube apparatus20, 22.

Inspection ports 24 and lights 26 mounted above sightglasses (not shown)allow the user to view the processing taking place inside the device 10.Access ports 28 allow manual access to the inside of the device 10. Thehousing 12 has reinforcing ribs 30 and support legs with adjustable feet32. A moisture sensor 34 is mounted on top of the device 10.

As shown in FIG. 2, each vertical agitator 36 is connected by a verticalshaft 38 to a final gear reduction box 40. A horizontal shaft 42 isattached to the bottom end of the vertical shaft 38, and forward prongs44 and rearward prongs 46 are attached to the horizontal shaft. Theforward prongs 44 are blunt. They are curved toward and located justabove first conveyor belt 48 (the stirring belt) and second conveyorbelt 50 (the salting belt). Line A represents the depth of the curdsbeing processed on the belts 48, 50. The forward prongs 44 scoop thecurds, while the rearward prongs 46 are dragged through and stir thecurds. Sideboards 52, which are shown in phantom in FIG. 2, keep thecurds on the conveyor belts 48, 50. The sideboards 52 are made ofplastic or other easily cleaned, corrosion-resistant material.

Any number of conveyor belts may be used with the present invention. Inits preferred embodiment, food processing device 10 uses two conveyorbelts, first conveyor belt 48 and second conveyor belt 50. The conveyorbelts 48, 50 are positioned in a step-wise, overlapping fashion toensure that all material is transferred from the first conveyor belt 48to the second conveyor belt 50 as the curds and whey move through theprocessing stages. Each conveyor belt 48, 50 allows the whey to bedrained from the curds, travels along belt carryways 54 and beltreturnways 56, is tensioned by a gravity belt takeup 58 and takeuprelease arm 60, and is mounted on belt drive and idler shafts 62.

A first belt scraper 64 is positioned at the second end (the downstreamend) of first conveyor belt 48, and a second belt scraper 66 ispositioned at the second end of second conveyor belt 50. The first beltscraper 64 and second belt scraper 66 ensure that the food is removedcompletely from the first conveyor belt 48 and the second conveyor belt50. A photoeye 68, which senses curd accumulation in auger trough 70, ispositioned at the second end of the second conveyor belt 50. Curds arecollected in auger trough 70, and may be removed from the device 10through curd outlet 72. A curd outlet auger 74 is located at the secondend of the second conveyor belt 50 to aid in removing the processedcurds. A moisture sensor 34 is positioned toward the second end of thesecond conveyor belt 50.

Curd wash headers 76 are located at the first end of the first conveyorbelt 48. A curd wash curtain 78 contains the liquid used in the curdwash. Vents 80 are located at the second end of the first conveyor belt48, midway along the top of the device 10. At the first end of the firstconveyor belt 48, an inlet deflector plate 82 is located next to thecurd and whey inlet 14. The first end of the inlet deflector plate 82 ispivotally mounted on top of the curd and whey inlet 14. The second endof the inlet deflector plate 82 is held in place by an inlet deflectorplate arm 84. Located below the inlet deflector plate 82 is a drainingscreen 86. In the preferred embodiment, the draining screen 86 is acommercially available wedge wire dewheying screen.

A first ramp 88 and a second ramp 90 are located under that portion ofthe second conveyor belt 50 that is under the salt tube apparatuses 22.The first ramp 88 and the second ramp 90 slope toward a salty wheyoutlet 92, where whey is collected from the curds after they have beensalted. The second ramp 90 meets a third ramp 94 at a peak 96. Sweetwhey that falls on the third ramp 94 runs in the opposite direction fromthe salty whey collected on the second ramp 90, and is collected at asecondary sweet whey outlet 97. A fourth ramp 98 is positioned under thefirst conveyor belt 48 to collect the sweet whey drained from the curdson the first conveyor belt 48 at a main sweet whey outlet 100. Each ofthe ramps 88, 90, 94, 98 also is optimally positioned to ensure properdrainage of the cleaning and rinsing solutions that are used when theclean-in-place procedures for the device 10 are followed.

Referring now to FIG. 3, it can be seen that each pair of verticalagitators 36 is driven by a single motor and primary gear reduction box102. Each motor and primary gear reduction box 102 is operably connectedto two final gear reduction boxes 40, one above each of two verticalagitators 36. It can be seen that each of the two vertical agitators 36that are rotated by the same motor and primary gear reduction box 102rotate in opposite directions, and each overlaps the area swept by theother. Each final gear reduction box 40 drives a single verticalagitator 36 and is suited to withstand lateral stresses imposed by thevertical agitator 36.

As best seen in FIG. 3, in the preferred embodiment of the device 10 thevertical agitators are spaced closer together toward the front end ofthe device 10, where curds and whey are deposited on the first conveyorbelt 48 by the curd and whey inlet 14. The curds cool as they move alongthe belts 48, 50, thus requiring less agitation from the verticalagitators 36. By increasing the spacing between vertical agitators 36 asthe curds and whey proceed through the device 10, fewer verticalagitators 36 are required by the device 10, thereby reducingmanufacturing and maintenance costs. The salting belt drive 104 drivesthe second conveyor belt 50, while the stirred curd belt drive 106drives the first conveyor belt 48. The curd outlet auger drive 108removes processed curds from the device 10.

Referring now to FIGS. 4 and 5, a cross-sectional view of the device 10is depicted. A sealed lip 110 is placed on each vertical shaft toprevent lubricating fluids from entering the housing 12 from the finalgear reduction box 40. It can be seen in FIG. 4 that the pairedhorizontal shafts 42 are 90° out of phase, in that, when the horizontalshaft 42 of one vertical agitator 36 is parallel to the cross-section ofthe device 10, the horizontal shaft 42 of the other vertical agitator 36is perpendicular to the cross-section of the device 10. Theconfiguration of the forward prongs 44 and rearward prongs 46 on thehorizontal shaft 42 most clearly can be seen in FIG. 5, which is a sideview of only one end of the horizontal shaft 42. As depicted, theforward prongs 44 are moving to the right-hand side of the figure, thusscooping curds from the belt 50 without physically damaging them. Therearward prongs 46 are dragged through the curds, thus stirring thecurds, also without causing physical damage.

Referring now to FIG. 6, a cross-sectional view of the device 10 isdepicted. Next to the belt is a catwalk 112. Mounted on top of thehousing 12 is the ventilation duct 18. FIG. 6 also depicts theinteraction between the two vertical agitators 36.

Referring now to FIG. 7, a salt dispenser 114 is connected to the tubeapparatus 20, 22. As can be seen in FIG. 8, an inlet filter 116 isconnected to a pump 118 by a first connecting tube 120. The pump 118 isconnected by a second connecting tube 122 to a high-efficiency filter124, which is connected by a third connecting tube 126 to the first endopening 128 of a Venturi pickup tee 130. The Venturi pickup tee 130 alsohas a middle end opening 132 and a second end opening 134. Although aVenturi pickup tee 130 is used in the preferred embodiment of theinvention, it is contemplated that other means for connecting the saltsupply to the airstream also would be suitable. Furthermore, althoughinlet filter 116 and high-efficiency filter 124 are desirable and areused in the preferred embodiment of the present invention, the use ofsuch filters is not necessary to practice the invention. The connectingtubes 120, 122, 126 also may be eliminated by connecting the componentsdirectly to one another or by other means without affecting the practiceof the invention.

A salt hopper 136 receives a supply of salt. In a preferred embodiment,the supply of salt is a polyhedral container capable of holding aquantity of salt therein. In the most preferred embodiment, the supplyis a salt container 138 that is a generally rectangular solid directlycoupled to the salt hoppers beneath it. If the supply is in the form ofa salt container 138, a probe assembly 140 may be mounted on the side ofthe salt container 138. The probe assembly 140 has an element thatdetects when the salt level in the hopper has fallen too low. The probeassembly 140 also may have a second element that detects when the levelof salt in the salt container 138 is at a maximum level. In analternative embodiment, the probe assembly may be mounted directly onthe side of the salt hopper 136.

The salt hopper 136 has steeply sloped sides to ensure the salt flowsfreely. In addition, a bin vibrator 142 is attached to the side of thesalt hopper 136. Drive means 144 also are attached to the side of thesalt hopper 136. A platform 146 is located adjacent to the salt hopper136 to provide access to the salt hopper 136.

Referring now to FIG. 9, a chamber member 148 is mounted directly belowthe bottom of the salt hopper 136. The bottom of the chamber member isconnected to the middle end opening 132 of the Venturi pickup tee 130. Amakeup inlet 150 is attached to the side of the chamber member 148 . Inthe preferred embodiment, where a plurality of salt hoppers 136 and thusa plurality of chamber members 148 are used, the makeup inlet 150 takesthe form of a tube that connects each of the chamber members 148. Drivemeans 144 are operably connected to a dispensing wheel 152 located andvertically oriented within the chamber member 148. The dispensing wheel152 has a plurality of large teeth 154, with large gaps 156 between theteeth 154. Air that enters the makeup inlet 150 first must pass througha makeup inlet filter 158.

Referring now to FIG. 10, the tube apparatus 20, 22 comprises hollowtubes 160. The top end of the tube apparatus 20, 22 is connected to thesecond end opening 134 of the Venturi pickup tee 130. In a preferredembodiment, the hollow tubes 160 have branches 162, so that the tubeapparatus 20, 22 has one hollow tube 160 at its top end, and then hasbranches 162 that separate the single hollow tube 160 at the top end ofthe tube apparatus 20, 22 into a plurality of hollow tubes 160 at thebottom end of the tube apparatus 20, 22. Each branch 162 diverges at thesame angle from the hollow tube 160, thereby ensuring that the salt isevenly dispensed at the branch 162. In a most preferred embodiment, eachtube apparatus 20, 22 has a branch 162 that yields two hollow tubes 160,each of which again has a branch 162 that yields two more hollow tubes160, thereby making a total of four distribution ends 164 for each tubeapparatus 20, 22.

Each distribution end 164 terminates in a duckbill-shaped portion 166,thereby spreading the salt over a wide area. In the preferredembodiment, a quantity sensor 168 is positioned above the food to beprocessed on the conveyor belt 50. The quantity sensor 168 determinesthe quantity of the food on the conveyor belt 50 to be salted and isoperably connected to the drive means 144, thereby ensuring that theamount of salt dispensed into the tube apparatus 20, 22 is in proportionto the quantity of food being processed.

FIG. 11 depicts a cross-sectional view of the device 10. Verticalagitators 36, as well as the motor and primary gear reduction box 102and final gear reduction boxes 40 that drive them, have been removed forclarity. When a plurality of tube apparatuses 22 are used, in thepreferred embodiment of the invention they are staggered to ensureuniform coverage over the width of the belt 50. Nevertheless, it iscontemplated that the invention may be practiced by arranging the tubeapparatuses 22 in any suitable manner. A quantity sensor 168 is mountedabove the curds to detect the quantity of the curds passing beneath thesalt tube apparatuses 22.

As shown in FIG. 11, various cleaning nozzles are located within thehousing 12. Spray balls 170 are mounted from the top of the housing 12along the length of the device 10 in order to clean the inside of thedevice 10. Spray bars 172 are located along the length of the device 10on the inside of the belts 48, 50. Each spray bar spans the width of thedevice 10, and thus is well-suited to clean the belts 48, 50. A sprayball 170 and a spray bar 172 are depicted in FIG. 11, but have beenomitted from the other figures to enhance clarity.

The operation of the device 10 now will be described. A mixture of curdsand whey is pumped from a processing vat through the curd and whey inlet14 into the food processing device 10. The inlet deflector plate 82spreads the curd and whey mixture so that it is distributed evenly ontothe draining screen 86. The inlet deflector plate 82 may be adjusted sothat its distance from the curd and whey inlet 14 is directlyproportional to the rate at which the curds and whey are beingintroduced into the device 10. The position of the inlet deflector plate82 is maintained by the inlet deflector plate arm 84. The drainingscreen 86 drains a substantial portion of the whey from the curd andwhey mixture. The whey runs onto the fourth ramp 98 and is collected atthe main sweet whey outlet 100.

The curds and remaining whey travel along the first conveyor belt 48,where they are subject to a curd wash from the curd wash headers 76 anda the presalt from presalt tube apparatus 20. Additional whey and thecurd wash liquid, in addition to whey extruded from the curds when thepresalt causes the curds to contract, runs onto the fourth ramp 98 andis collected at the main sweet whey outlet 100.

As the curds travel along the first conveyor belt 48, they are stirredby vertical agitators 36. Forward prongs 44 scoop while stirring,thereby avoiding physical damage to the curds and ensuring that thecurds are processed into a uniform size. Rearward prongs 46 further stirthe curds, also without physically damaging them. A temperature sensor16 is mounted at the end of first conveyor belt 48 and operablyconnected to means for forcing cool air through the ventilation ductwork18, thereby automatically ensuring that the curds are processed at theproper temperature.

The conveyor belts 48, 50 may be operated at speeds from approximately0.333 feet per minute (fpm) to approximately 2 fpm, with a preferredrate of speed of approximately 1 fpm. The vertical agitators 36 may beoperated from approximately 7.5 rotations per minute (rpm) toapproximately 30 rpm, with a preferred rate of 15 rpm.

Upon reaching the end of the first conveyor belt 48, the curds and wheyare deposited on the second conveyor belt 50. A first belt scraper 64ensures that all curds and whey are removed from the first conveyor belt48 and deposited on the second conveyor belt 50.

Vertical agitators 36 continue to stir the curds as they travel alongthe second conveyor belt 50. Whey that is drained from the curds towardthe first end of the second conveyor belt 50 runs onto the third ramp 94and is collected at the secondary sweet whey outlet 97. After passingover the peak 96, salt is applied to the curds by a plurality of salttube apparatuses 22. The salting causes further contraction of thecurds, thus forcing out more whey. Whey that is separated from the curdsafter the curds pass the peak 96 runs onto the first ramp 88 and thesecond ramp 90 and is collected at the salty whey outlet 92.

The moisture sensor 34 detects the moisture content of the curds nearthe end of the processing in the device 10. Adjustments thus may be madepromptly if the curd moisture levels are not within the propertolerances. Upon reaching the second end of the second conveyor belt 50,the fully processed curds are deposited into the auger trough 70. Thesecond belt scraper 66 ensures that the processed curds are removed fromthe second conveyor belt 50. The processed curds may be removed from-thedevice 10 through the curd outlet 72 with the aid of the curd outletauger 74. In the event the curds begin accumulating in the auger trough70, when they reach the height of the photoeye 68, the photoeye 68 willdetect the accumulation and stop the device 10.

While the curds are travelling through the device 10, salt is flowingfrom the salt container 138 into the salt hopper 136, which deposits thesalt into the upper portion of the chamber member 148 and onto thedispensing wheel 152. The salt fills the gaps 156 between the teeth 154of the dispensing wheel 152. As the dispensing wheel 152 is turned bythe drive means 144, the salt is moved from above to below thedispensing wheel 152, where it then leaves the chamber member 148 andenters the middle end opening 132 of the Venturi pickup tee 130. Thequantity sensor 168 measures the quantity of food being processed on thebelt and sends a signal to the drive means 144, thus operating the drivemeans 144 faster as the quantity of food being processed on the conveyorbelt 50 increases.

At the same time, pump 118 pulls air through inlet filter 116, and thenforces the air through the high-efficiency filter 124. The air thenenters the Venturi pickup tee 130 through its first end opening 128, andleaves through its second end opening 134. As the air passes through theVenturi pickup tee 130, it creates a partial vacuum in the middle endopening 132 and in the chamber member 148. This partial vacuum sucks thesalt into the middle end opening 132 of the Venturi pickup tee 130,where it then is conveyed in the airstream out the second end opening134 of the Venturi pickup tee 130. A stream of air is provided to conveythe salt from the bottom of the chamber member 148 into the middle endopening 132 of the Venturi pickup tee 130. This airstream enters thechamber member 148 through makeup inlet 150 after being passed throughmakeup inlet filter 158.

After passing through the second end opening 134 of the Venturi pickuptee 130, the salt is conveyed into the hollow tubes 160 of the tubeapparatus 20, 22. The salt is distributed evenly over the branches 162and passes to the distribution ends 164, where it is spread by theduckbill-shaped portions 166 over the food being processed on theconveyor belt 48, 50.

Although the description of the preferred embodiment has been presented,it is contemplated that various changes may be made without deviatingfrom the spirit of the present invention. Accordingly, it is intendedthat the scope of the present invention be dictated by the appendedclaims, rather than by the description of the preferred embodiment.

We claim:
 1. A method for processing cheese curds, comprising conveyingthe curds upon a conveyor belt while stirring the curds withoutphysically damaging them, said stirring comprising stirring with aplurality of agitators comprising blunt prongs.
 2. The method of claim1, further comprising draining liquid through the conveyor belt.
 3. Themethod of claim 2, wherein the act of stirring comprises revolving saidblunt prongs around at least one axis of rotation, the act of revolvingbeing accomplished by operating a motor that is operably connected tothe blunt prongs.
 4. The method of claim 3, wherein the at least oneaxis of rotation has top and bottom ends, the bottom ends being closerthan the top ends to the curds to be stirred.
 5. The method of claim 4,wherein the at least one axis of rotation intersects the upper surfaceof the curds being stirred.
 6. The method of claim 5, wherein the atleast one axis of rotation is generally perpendicular to the plane ofthe upper surface of the curds being stirred.
 7. The method of claim 1,further comprising applying salt to the curds.
 8. The method of claim 1,further comprising collecting whey drained from the curds.
 9. The methodof claim 1, further comprising dispensing curds and whey onto a firstend of the conveyor belt through an inlet.
 10. The method of claim 9,further comprising draining whey from the curds through a drainingscreen positioned under the inlet.
 11. The method of claim 1, furthercomprising, forcing air through ductwork, thereby allowing thecirculation of air to maintain the curds at a proper temperature. 12.The method of claim 1, further comprising depositing the curds from theconveyor belt into an auger trough and then removing the curds from theauger trough.
 13. The method of claim 12, further comprising stoppingthe conveyor belt if there is excessive accumulation of curds in theauger trough.
 14. The method of claim 1, further comprising detecting amoisture level of the curds and adjusting the moisture level if themoisture level does not meet a predetermined level.
 15. The method ofclaim 7, wherein the act of applying salt to the curds comprisessupplying salt to a salt receptacle, transferring the salt from the saltreceptacle to a salt dispenser, and conveying the salt from the saltdispenser to the curds being processed, wherein the salt is conveyed bypumping air through a tube apparatus from the salt dispenser to thecurds.
 16. The method of claim 15, further comprising depositing salt inan upper portion of a chamber member of the salt dispenser and rotatinga dispensing wheel that is placed in the chamber to move the salt fromabove to below the dispensing wheel.
 17. The method of claim 16, furthercomprising allowing air and salt to pass through openings in thedispensing wheel.
 18. The method of claim 16, wherein the dispensingwheel is rotated with a motor.
 19. The method of claim 18, furthercomprising, varying the speed of the motor.
 20. The method of claim 15,further comprising creating a partial vacuum in an opening of a Venturipickup tee and sucking the salt from the salt dispenser with the partialvacuum into the Venturi pickup tee, wherein the act of pumping includesproviding a stream of air that carries the salt from the Venturi pickuptee to the tube apparatus.